Tuesday, November 29, 2005

Fish in a barrel, I tell you

More on the actual analysis of the (quite substantial and IMO quite obvious) subtext of this one later but I couldn't resist this. Aaro gets didactic and decides to patronise us all by showing us how to deal with numbers in news stories:

Five-sixths of all the men who felt strongly enough about the possible paternity of their children that they went for tests found out that their suspicions were unfounded. That is 84 per cent.

Five divided by six is 0.8333. That's 83 per cent, not 84. The actual figure (based on 3034 successful challenges out of 15909 tests) is 81%. I suspect that what Aaro has done is pick up the factoid "nearly one-sixth", convert 1/6 to a decimal on his calculator (0.166667) and subtract 16 from 100 to get 84. Sloppy work, D minus, see me after class. As Dave sez:

THERE IS AN iron rule for big stories involving percentages: always reverse them

That's the "iron rule". The "golden rule" is get the fucking numbers right first, softlad.